Printing plate



W. F. HUCK PRINTING PLATE Oct. 4, 1938.

Original Filed Dec. 31, 1934 All l/j 111D INVENTOR.

Patented Oct. 4, 1938 UNI.TE DSTATE s PATENT OFFICE 1 No. 759,983. Divided and this applicationAugust 21,1937, Serial No. 160,327 v 1 10 claims. ((11. 101- 395) This is a divisional application of the co-periding William' F. Huck application, Serial No. 759,983; forv Stereotype plate casting molds, filed December 31, 1934, and the present, invention relatesto printing-plates of the type disclosed in the above identified application, and, also, disclosed in the William F. Huck Patent No. 2,050,950, granted August 11, 1936,'and which eventuated out of application Serial No. 759,982 filed December 31,1934. In existing rotary printing 1 machines, the icurved or arcuate stereotype or electrotype printing plates are clamped or locked to the periphery of the printingor form cylinders, andparticularly rotary newspaper printing machines, by arcuate clamp members or ring segments, and these arcuate clamp members are moved longitudinally oraxially along the cylinders into locking engagement with the curved ends of the printing plates, thereby locking or clamping the opposed *c'urved ends of each plate to its cylinder. The 1 printing plates are further held against motion around the plate cylinders by marginbars which 1 1 are secured on theperipheral portion of the When the plates are clamped to the plate cylin- 1 ders, the straight longitudinal edges of the plates cylinders and extend longitudinally thereof.

engage or 1ab ut the longitudinal edges of the margin bars, thereby preventing movement of the plates around the cylinders, but, however, the margin bars do not secure the plates'against radial movement, such as may be produced by centrifugal force when the printing cylinders are rotated at relatively high operating speeds.

Thismeans ofsecuring the printing plates to the plate: cylinders is commercially satisfactory 1 when the printing presses are run at commercial speeds heretofore acceptable. However, there is 1a progressively increasing demand for higher operating speeds for rotary printing machines,

1 1 and in designing rotary printing machines'to meet thisdemand, it is necessary to provide additional "scuringa or clamping means for each printing Another object of: this invention is to provide a semi-cylindrical printing plate whichis con- 50 structed and. arranged'so 'thatits straight axial edges interlock with specially constructed margin ybarsawhereby the opposed axial edges of the plate are rigidly secured to the plate or formfcylinder of a 'rotaryr printing machine;..

Atfurthen object of this invention is toiprovide opposed axial edges constructed and arranged for interlocking engagementwith diametrically opand theplate being constructed and arranged for I a semi-cylindrical printing plate which has'its posed axially-extending margin bars carried by the peripheral'portion of a plate or form cylinder, 7 a

cooperable engagement with instrumentalities for 1.

positively forcing the axial edges of the plate to interlocking engagement with'the margin bars.

A more specific object of this invention is the provision of a cast curved printing'plate which is constructedand arranged so that itsopposed arcuate edges may beengaged by the conven tional' arcuate plate clamps to rigidly secure these arcuate terminals of the plate to a plate or form cylinder, and the opposed straight axialedges'of the plate being constructed and arranged for interlocking engagement with specially constructed margin bars without interfering with the construction or operation of the said conventional instrumentalities for locking the arcuate edges of the plate to the cylinder. 3 f

It is also an object of this invention toprovide a rigidourved printing plate of generally-im proved construction and arrangement, whereby the device will be simple durable and-inexpensive inconstruction, as well as convenient, practical, serviceable and efficient in its use. r 1 With the foregoing and-other objects in view,

which will appear as the description proceeds; the invention resides in the combinationand arrangement of-p'arts and in the details of construc resorted to within the scope of theclaims without departing from the spirit or sacrificing any advantages of the invention. a

For a complete disclosure of the invention a detailed description of the improved printing plate will now be given in connection withthe accompanying drawing forming a part of this specifica tion, wherein: 1 1

1 Figure 1 is a plan view of the improved stereotype printing plate,the printing or image-producing characters being omitted; 1

Figure 2 is a transverse sectional view taken on the line 22 of Figure 1;- V 1 Figure 3 is a fragmental longitudinal sectional View taken on the line 3.3of Figure 2;

' Figure 4 is a transverse sectional view of a slightly'modified form of the invention; and

Figure 5 is a fragmental transverse sectional View of a plate or form cylinder having plate securing or locking mechanism, oian approved type, for securing the straight axial edges of the printing plate to the cylinder.

Referring to the drawing, in which similar reference characters designate corresponding parts,

plate clamps or rings engage the beveled arcuate edges l I of the plate to secure these edges ofthe plate to the plate or form cylinder l2, and inasmuch as the construction and operation of the conventional clamps which engage the beveled arcuate terminals ll of the plate Hlare ,well understood by those skilled in the art and form no part of this invention, such clamp members have not been illustrated in the drawing of this application.

At low or intermediate operating speeds of the plate cylinder l2, the conventional arcuate clamping rings which engage the beveled terminals H of the plate are sufiicient to hold the plate It) to the cylinder I2. At higheroperating speeds of the plate cylinder, however, centrifugal. force tends to bend or force the intermediate portion of each plate l0 outwardly away from the cylinders l2, and if this bending strain is of sufficient amplitude the platewill fly from its cylinder l2 and frequently results in damage to the machine or injury to the operator.

In order to provide a plate which will'be securely locked to the cylinder, along its straight axial edges as well as along its conventional beveled arcuate edges, the, plate lllis provided with a beveled projection 13 which extends circumferentially from each straight axial edge of the plate l0. Each projection or extension Isis formed by cutting away the entire outer. portion of each axial edge of the printing plate, as indicated at l5, and each extension 13, forms a continuation of the inner arcuate surface of the plate Spaced apertures or recesses l6 are formed in the inner face of the plate I!) to define radially extending shoulders ll which are positioned ad,- jacent the beveled projections l3. Each plate is also provided with aplurality of spacedarcuate circumferentially extending shavingor trimming ribs M of conventional construction well understood by those skilled in the art. In order to secure the straight axial edges of the plates ID to a plate or form cylinder l2, clamping or-locking mechanism of the type indicated in the; Patent No. 2,050,950 is employed. Each locking mechanism includes a margin bar l8 having its opposed I axially-extending edges cut away to define overhanging beveled projections or extensions 20 for engagement with the-beveled projections or extensions I3 of the plate It], as will be hereinafter more fully explained. Spaced longitudinally extending shafts 2| are rockably secured to the cylinder I2, as indicated at .22, and each shaft 2| has a pawl or looking finger 23 extending radially therefrom.

In order to secure the plates It! to a cylinder 52, the plates are positioned'one at a time on the cylinder l2, in conformity with. the usual practice, and the selected shafts 22 are rocked or oscillated sufliciently to cause the locking pawls or fingers 23 to move into the aperturesor recesses E0 to engagement with the shoulder ll of the. opposed axial terminal of each plate to therebycause the The arcuate terminals of the plate l0 beveled projections l3 of the opposed axial terminal of each plate ID to move under and to locking engagement with the beveled extension 20 of the margin bars l8, so that each axial terminal of each plate I0 is rigidly secured or locked to the plate cylinder l2. Each shaft 22 has a lever 24 secured thereto, and this lever is operably engaged by mechanism of the type disclosed in Patent No. 2,050,950, to rock the shaft 22 and finger 23 to plate locking position and to securely hold them in locking position, but, inasmuch as the locking and actuating mechanism does not 7 form apart of this invention the complete means for rocking and locking the shafts 22 have not been illustrated in the drawing of this application. By this arrangement, both axial edges of each plate. are securely locked to the plate cylinder l2,

. and inasmuch as the beveled arcuate edges ll of each plate are also secured to the cylinder by the conventional clamping means, all edges of the plate are held against outward movement to prevent the plate from being thrown from the cylinder by centrifugal force set up by the high cylinder speeds.

The modified form of the invention disclosed in Figure 4 is similar to the form disclosed in Figure 2, except the shoulders I? are formed on lugs or bosses I6 instead of being formed by recessing the inner face of the plate. In securing a plate of the type disclosed in Figure 4 to the printing cylinder l2, the locking pawls or fingers 23 engage the shoulders ll" and force the beveled extensions !3 of the axial edges of the plate to locking engagement with the margin bars H! in the manner which has been hereinbefore explained.

From the foregoing it is manifest that applicant has provided a simple stereotype printing plate capable of having its straight axial edges rigidly secured to the printing cylinder to thus aid in holding the plate against outward movement away from the cylinder. By locating the shoulders 51 or ill immediately adjacent the beveled projections S3 of the plate W, the clamping pawls or fingers 23 may operably engage these shoulders with relatively great stress to securely force the projections 13 to locking engagement with the overhanging beveled projections 20 of the plate cylinder margin bars 18 to thereby rigidly secure the straight axial edges of each plate to the plate cylinder without danger of buckling or bending the plate. Furthermore, by locating radial shoulders I! or ll" immediately adjacent the projections l3 and rigidly engaging these shoulders by the fingers or pawls 23, each plate i0 is securely held against tangential movement away from the margin bar l8, and, also against radial movement away from the cylinder.

7 It will be understood that the invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof, and it is therefore desired that the present embodiments be considered in' all respect as illustrative and not restrictive and it will be further understood that each and every novel feature and combination present in or possessed by the method and mechanism herein disclosed forms a part of the invention included in this specification.

Having thus described my invention, what I claim as new and useful is:

1. As an article of manufacture, a semi-cylindrical printing plate having reduced projections extending circumferentially from the straight edges thereof, and shoulders formed on the inner "Z6 face of the printing plate immediately adjacent the projections.

2. As an article of manufacture, a semi-cylindrical plate having the entire outer portions of its straight edges removed to define reduced projections extending circumferentially from the straight edges, the projections forming continuations of the inner peripheral surface of the semicylindrical printing plate, and shoulders formed on the inner face of the printing plate immediately adjacent the said projections.

3. As an article of manufacture, a semi-cylindrical printing plate having reduced projections extending from and coextensive with the straight edges thereof, the projections forming continuations of the inner peripheral surface of the semicylindrical printing plate, and recesses formed in the inner face of the printing plate to define shoulders positioned immediately adjacent the said projections.

4. A cast semi-cylindrical printing plate having reduced projections extending circumferentially from and coextensive with the straight edges thereof, and shoulders formed at the inner face of the printing plate immediately adjacent the projections. V

5. A cast semi-cylindrical printing plate having reduced projections extending circumferentially from and coextensive with the straight edges thereof, recesses formed in the inner face of the plate to form shoulders located immediately adjacent the projections.

6. A cast semi-cylindrical printing plate having reduced projections extending circumferentially from and coextensive with the straight edges thereof, lugs formed on the inner face of the plate to form shoulders located immediately adjacent the projections.

7. A semi-cylindrical stereotype printing plate having reduced beveled projections extending circumferentially from the straight edges thereof, and radial shoulders formed at the inner face of the plate immediately adjacent the beveled projections.

8. A semi-cylindrical stereotype printing plate having the outer portions of its straight edges removed to form reduced circumferentially-extending projections which form continuations of the inner face of the plate, and radial shoulders formed at the inner face of the plate immediately adjacent the beveled projections.

9. A semi-cylindrical stereotype printing plate having the entire outer portions of its straight edges removed to form reduced beveled projections on the straight edges of the plate, and spaced radial shoulders formed at the inner face of the plate immediately adjacent the beveled projections.

10. A semi-cylindrical stereotype printing plate having the entire outer portions of its straight edges removed to form reducedprojections on the straight edges of the plate coextensive therewith and each projection being beveled outwardly from the straight edge of the plate to the outer portion of the projection, and shoulders formed at the inner face of the plate immediately adjacent the projections.

WILLIAM F. HUCK. 

